Problem: The grades on a geometry midterm at Gardner Bullis are normally distributed with $\mu = 67$ and $\sigma = 2.5$. Daniel earned a $73$ on the exam. Find the z-score for Daniel's exam grade. Round to two decimal places.
Explanation: A z-score is defined as the number of standard deviations a specific point is away from the mean We can calculate the z-score for Daniel's exam grade by subtracting the mean $(\mu)$ from his grade and then dividing by the standard deviation $(\sigma)$ $ { z = \dfrac{x - {\mu}}{{\sigma}}} $ $ { z = \dfrac{73 - {67}}{{2.5}}} $ ${ z \approx 2.40}$ The z-score is $2.40$. In other words, Daniel's score was $2.40$ standard deviations above the mean.